Of all the fighter planes that flew during World War II, the P-39 Airacobra was unique in having its engine place behind the pilot. This design allowed for greater manoeuvrability. The P-39 was the first single-engine fighter plane to have a tricycle undercarriage and to have a more powerful armament than any other single-engine fighter of that time.

The P-39 Airacobra was designed in 1937, and first flew on April 6, 1939. Nearly 9,588 P-39 series were built, and flown by the U.S. Army, U.S. Air Force squadrons in the Pacific, Alaska, Europe, Africa, and South America. The British, Free French, Italian Air Forces also operated P-39's.